Fix: reset allowance query (#429)

Otherwise allowance state is persisted between tokens

src/ui/pages/SwapForm/SwapForm.tsx

@@ -266,7 +266,7 @@ export function SwapForm() {
     spender: quote?.token_spender ?? null,
     contractAddress,
     enabled: quotesData.done && Boolean(quote && !quote.enough_allowance),
-    keepPreviousData: true,
+    keepPreviousData: false,
   });
 
   const signerSenderRef = useRef<SignerSenderHandle | null>(null);